Mechanical drill.



PATENTED NOV. 17, 1903.

G. B. PICKUP.

MECHANICAL DRILL.

APPLIOATION FILED JAN. 1s, 1902.

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UNITED STATE-s Tatented November 1'7, 1903;.

PATENT OEEICE.

GEORGE B. PICKOP, OF NEW BRITAIN, CONNECTICUT, ASSIGNOR TO P. 85 F.

CORBIN, OF NEW BRITAIN, CONNECTICUT, A CORPORATION OF CON- NECTICUT.

MECHANICAL DRILL.

srncFIcA'rIoN forming per@ of Lettere Patent Ne. 744,396, dated November V17, 1903.

Application iled January 18, 1902. Serial No. 96.241. (No modela To al?, whm t may concern..-

Be it known that I, GEORGE B. PIOKOP, a citizen ofv the United States, residing at New Britain, county ofHartford, State of Connecticut, have invented certain new and useful Improvements in Mechanical Drills, of which the following is a full, clear, and exact description.

My invention relates to drilling-machines.

The object of my invention is to provide an improved means whereby the feed of a drill into material to be bored will be automatically checked in theevent the drill is too dull to accomplish its function properly or in the event the materialv to be bored is so hard as to endanger the breaking of the drill.

In the drawings, Figure 1 is a side elevation Fig'. 2 is a front elevation of the same. Fig. 3 is a section on the line 3 3. Fig. 4 isaside elevation of parts of the mechanism shown in Fig. 1,said parts being in a dierent position from that shown in said figure. Fig. 5 lincludes a side and section elevation of a single detail of construction.

In the particular form of mechanism shown 1 isasuitable frame or standard. 2lisatable carried thereby and upon which the work may be placed.

3 is a block of material to bedrilledor bored and in position underneath the drill 4.

5 is a carrier. f

6 is a shaft revolubly mounted in the car-` rier 5 and provided with a suitable chuck at its lower end to hold the drill 4. Theshaft 6 is incapable of longitudinal movement independent of the carrier 5, but may revolve therein. may be moved longitudinally in a guide 7, but it does not rotate therein.

8 is a rack on the rear of the guide 7.

9 is a pinion meshing with the rack 8.

10 is a shaft carrying the pinion.

11 is what I shall term a contact device. The said contact device 11 is fixed upon the shaft 10.

12 is a stop-supporting member iixed upon some suitable part of the frame or projection therefrom. (See Fig. 3.)

121 is a stop carried by member 12. The

stop 121 stands in the path of movement of The carrier 5 is mounted so that ita projection or tooth 111 upon the contact device 11. vated position, one of the teeth 111 may bear against the stop 121. l

13 is alever-arrn, the hub ofwhich is loosely mounted upon'the shaft 10.

14 is a contact member carried by the arm 13 and adapted lto detachably connect said arm` 13 with the device 1l.

In the particular construction shown herein 15 is a spring carried in a suitable box 16 on arm 13, the tension of which spring is governable by an adjusting-screw 17. The spring bears against the inner end of the contact member 14. The outer end or nose of the device 14 is preferably tapered or pointed, as best shown in Fig. 4, to present two inclined surfaces which may engage in a notchin the contact device 11,forexa'mple,such a notch as shown between the teeth 111 111. It will be seen that when the nose of the contact member '14 is in the aforesaid notch the parts are coupled together, the degree of resistance necessary to break said connection being variable according to the adjustment of the spring 15.

18 isa pin or bearing on the arm 13, against which a cam 19 may bear.

20 is a spring adaptedto cause'the pin 18 to bear against the perimeter of the cam 19 and followits irregularities. The cam 19 is mounted upon a suitable revoluble shaft 21.

22 is a pulley mounted on shaft 6 and connected thereto by a feather spline, allowing the shaft to move up and down in said pulley.

23 is a spring located between the pulley 22 and the head 61 of the shaft 6. The spring 23 in the particular form shown is a coilspring normally adapted to expand. Consequently it tends to lift'the shaft 6 and the drill 4; but its power is not enough to overcome the positive action of the cam 19, which depresses said shaft through the connections aforesaid. It should be'understood that I regard a counterweight as the -fulljeojuivalent When the drill'` is in its most ele.

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the contact member 14 to be engaged with the contact device 11. Also assume that a block of metal of a quality too hard to be bored is in position under the drill 4. When the machine is started, the cam 19 revolves, rocking the arm 13. The forward movement of the latter rotates the shaft 10, and thereby causes the depression of the carrier 5 and shaft 6 until the drill 4 is brought into contact with the unduly hard material. The resistance oiered by this metal is such that the downward feed of the drill 4 is stopped; but inasmuch as the other parts continue to move the cam forces the arm 13 ahead and breaks the connection between the contact device 11 and the contact member 14, the nose of the latter slipping out of the notch in the former. The spring 23 then elevates the carrier 5, the drill and its associated parts, and the tooth or projection 111 on the device is returned to its starting position against the stop 121. As the cam 19 continues revolving, the arm 13 is rocked forwardly and backwardly, but the drill remains stationary. If the pull of the spring 2O were strong enough, it would cause the contact member 14 to snap into the notch between said teeth 111, 111at each retraction of the arm 13, but it is preferred that the pull of the spring 2O be insufficient to ecct this connection, thereby avoiding undue wear of the parts. Were it effected, the action of the parts would be repeated as before-that is, the connection would be broken when the drill reached the impenetrable material and the parts would return to the starting position, as before described. As soon as the operator detects the fact thatany particular drill is not working he ascertains the reason, corrects the fault, waits until the low point in the cam is reached,and then manually forces the leverarm 13 back until the member 14 snaps into the notch between the teeth 111 on device 11.

I claim- 1. In a drilling-machine, a reciprocatory carrier, means for normally retracting said carrier, a controlling device including a rack, pinion and a lever-arm concentric with said pinion, means for moving said lever-arm to and fro, and a spring-pressed detent having a one-point connection, saidl detent being located between the lever-arm and the carrier to hold the arm in its operative connection or entirely release it therefrom.

2. In a drilling-machine, a reciprocatory carrier, a guide therefor, a rack for said carrier, a pinion in mesh with said rack, a contact device connected with said pinion, a 1ever-arm concentrically and rotatably mounted with relation to said contact device and said pinion, and a detent carried by said lever-arm having a one-point connection with said contact device for holding the parts in their operative connections or releasing them therefrom. g

3. In a drilling-machine, a reciprocatory carrier, a guide therefor, a rack for said carrier, a pinion revolubly mounted and in mesh with said rack, a contact device connected with said pinion, a lever-arm mounted to move with said contact device at certain times, but independent thereof at other times, said lever and contact device having a common axis of rotation, a detent carried by the lever-arm having a one-point connection with the contact device whereby the lever-arm may move with it but independent of the contact device, means for moving said lever-arm and means for varying the pressure of engagement between the detent and the contact device.

4. In au apparatus of the character described, a movable carrier, a guide therefor, a rack and pinion,a lever-arm mounted concentricrwith said pinion, a. cam for swinging said lever-arm, means to cause said leverarm to normally move toward said cam and ayielding detent having a one-point connection between the lever and the pinion whereby the movement of the carrier may be automatically checked and the arm retracted independently of the carrier.

Signed at -New Britain, Connecticut, this 15th day of January, 1902.

GEORGE B. IICKOP.

Witnesses:

G. ERNEST RooT, C. A. BLAIR. 

